While a mouse device is used to edit electronic documents, make electronic engineering drawings or play computer games, the user's palm is usually placed on an armrest of the mouse device. Since the user's palm is supported on the armrest of the mouse device, the user can move the mouse more easily and use the finger to press the button of the mouse device.
Conventionally, a mouse device comprises a mouse body, a roller module and a button module. The roller module and the button module are installed on the mouse body. The mouse body has an armrest region beside the button module and the roller module. The user's palm can be supported on the armrest region.
However, the conventional mouse device still has some drawbacks. For example, the sizes of the palms of different users are not identical, and the volume of the conventional mouse device is fixed. Since it is impossible to adjust the volume of the mouse device according to the size of the user's palm, the comfort of using the mouse device is usually unsatisfied to the user.